Adsorption of uranyl ion on hexagonal boron nitride for remediation of real U-contaminated soil and its interpretation using random forest.

Acid leaching has been widely applied to treat contaminated soil, however, it contains several inorganic pollutants. The decommissioning of nuclear power plants introduces radioactive and soluble U(VI), a substance posing chemical toxicity to humans. Our investigation sought to ascertain the efficacy of hexagonal boron nitride (h-BN), an highly efficient adsorbent, in treating U(VI) in wastewater. The adsorption equilibrium of U(VI) by h-BN reached saturation within a mere 2 h. The adsorption of U(VI) by h-BN appears to be facilitated through electrostatic attraction, as evidenced by the observed impact of pH variations, acidic agents (i.e., HCl or H2SO4), and the presence of background ions on the adsorption performance. A reusability test demonstrated the successful completion of five cycles of adsorption/desorption, relying on the surface characteristics of h-BN as influenced by solution pH. Based on the experimental variables of initial U(VI) concentration, exposure time, temperature, pH, and the presence of background ions/organic matter, a feature importance analysis using random forest (RF) was carried out to evaluate the correlation between performances and conditions. To the best of our knowledge, this study is the first attempt to conduct the adsorption of U(VI) generated from real contaminated soil by h-BN, followed by interpretation of the correlation between performance and conditions using RF. Lastly, a. plausible adsorption mechanism between U(VI) and h-BN was explained based on the experimental results, characterizations, and a. comparison with previous adsorption studies on the removal of heavy metals by h-BN.

Observation of Highly Anisotropic Thermal Expansion of Polymer Films.

While dimensional change under thermal loading dictates various device failure mechanisms in soft materials, the interplay between microstructures and thermal expansion remains underexplored. Here, we develop a novel method to directly probe the thermal expansion for nanoscale polymer films using an atomic force microscope as well as confining active thermal volume. In a model system, spin-coated poly(methyl methacrylate), we find that the in-plane thermal expansion is enhanced by 20-fold compared to that along the out-of-plane directions in confined dimensions. Our molecular dynamics simulations show that the collective motion of side groups along backbone chains uniquely drives the enhancement of thermal expansion anisotropy of polymers in the nanoscale limit. This work unveils the intimate role of the microstructure of polymer films on its thermal-mechanical interaction, paving a route to judiciously enhance the reliability in a broad range of thin-film devices.

Comparison of sampling methods in assessing the microbiome from patients with ulcerative colitis.

BACKGROUND: Dysbiosis of ulcerative colitis (UC) has been frequently investigated using readily accessible stool samples. However, stool samples might insufficiently represent the mucosa-associated microbiome status. We hypothesized that luminal contents including loosely adherent luminal bacteria after bowel preparation may be suitable for diagnosing the dysbiosis of UC. METHODS: This study included 16 patients with UC (9 men and 7 women, mean age: 52.13 ± 14.09 years) and 15 sex- and age-matched healthy individuals (8 men and 7 women, mean age: 50.93 ± 14.11 years). They donated stool samples before colonoscopy and underwent luminal content aspiration and endoscopic biopsy during the colonoscopy. Then, the composition of each microbiome sample was analyzed by 16S rRNA-based next-generation sequencing. RESULTS: The microbiome between stool, luminal contents, and biopsy was significantly different in alpha and beta diversities. However, a correlation existed between stool and luminal contents in the Procrustes test (p = 0.001) and Mantel test (p = 0.0001). The stool microbiome was different between patients with UC and the healthy controls. Conversely, no difference was found in the microbiome of luminal content and biopsy samples between the two subject groups. The microbiome of stool and lavage predicted UC, with AUC values of 0.85 and 0.81, respectively. CONCLUSION: The microbiome of stool, luminal contents, and biopsy was significantly different. However, the microbiome of luminal contents during colonoscopy can predict UC, with AUC values of 0.81. Colonoscopic luminal content aspiration analysis could determine microbiome differences between patients with UC and the healthy control, thereby beneficial in screening dysbiosis via endoscopy. TRIAL REGISTRATION: This trial was registered at http://cris.nih.go.kr . Registration No.: KCT0003352), Date: 2018-11-13.

Percutaneous Trans-splenic Obliteration for Duodenal Variceal bleeding: A Case Report.

Duodenal varices are a serious complication of portal hypertension. Bleeding from duodenal varices is rare, but when bleeding does occur, it is massive and can be fatal. Unfortunately, the optimal therapeutic modality for duodenal variceal bleeding is unclear. This paper presents a patient with duodenal variceal bleeding that was managed successfully using percutaneous trans-splenic variceal obliteration (PTVO). A 56-year-old man with a history of alcoholic cirrhosis presented with a 6-day history of melena. Emergency esophagogastroduodenoscopy revealed a large, bluish mass with a nipple sign in the second portion of the duodenum. Coil embolization of the duodenal varix was performed via a trans-splenic approach (i.e., PTVO). The patient no longer complained of melena after treatment. The duodenal varix was no longer visible at the follow-up esophagogastroduodenoscopy performed three months after PTVO. The use of PTVO might be a viable option for the treatment of duodenal variceal bleeding.

A Neural Network-Based Gait Phase Classification Method Using Sensors Equipped on Lower Limb Exoskeleton Robots.

An exact classification of different gait phases is essential to enable the control of exoskeleton robots and detect the intentions of users. We propose a gait phase classification method based on neural networks using sensor signals from lower limb exoskeleton robots. In such robots, foot sensors with force sensing registers are commonly used to classify gait phases. We describe classifiers that use the orientation of each lower limb segment and the angular velocities of the joints to output the current gait phase. Experiments to obtain the input signals and desired outputs for the learning and validation process are conducted, and two neural network methods (a multilayer perceptron and nonlinear autoregressive with external inputs (NARX)) are used to develop an optimal classifier. Offline and online evaluations using four criteria are used to compare the performance of the classifiers. The proposed NARX-based method exhibits sufficiently good performance to replace foot sensors as a means of classifying gait phases.

Age and gender are important considerations in choosing the sniffing position for laryngoscopic view.

AIMS: The sniffing position is considered to be the standard position for direct laryngoscopic viewing. This crossover study evaluated age and gender as variables in comparing the benefits of the sniffing position over simple head extension for laryngeal view during direct laryngoscopy. METHODS: Laryngoscopy with a curved blade was performed on 200 anesthetized adults (100 males, 100 females) presenting for routine elective surgery. Glottic visualization was assessed by using the percentage of glottic opening (POGO) score in both simple extension and sniffing positions without the aid of the assistant or external laryngeal manipulation. Each gender group was divided into a younger group (< 50 years) and an older group (≥ 50 years). POGO scores were compared between both positions within each group. RESULTS: Mean (SD) POGO scores increased significantly only in younger male patients from 43% (39%) in the head extension position to 76% (30%) in the sniffing position. CONCLUSION: The sniffing position seems to be advantageous for getting a better laryngeal view during laryngoscopy for tracheal intubation in adult male patients less than 50 years old.

Brief biomechanical analysis on the walking of spinal cord injury patients with a lower limb exoskeleton robot.

This paper presents a brief biomechanical analysis on the walking behavior of spinal cord injury (SCI) patients. It is known that SCI patients who have serious injuries to their spines cannot walk, and hence, several walking assistance lower limb exoskeleton robots have been proposed whose assistance abilities are shown to be well customized. However, these robots are not yet fully helpful to all SCI patients for several reasons. To overcome these problems, an exact analysis and evaluation of the restored walking function while the exoskeleton is worn is important. In this work, walking behavior of SCI patients wearing the rehabilitation of brain injuries (ROBIN) lower-limb walking assistant exoskeleton was analyzed in comparison to that of normal unassisted walking. The analysis method and results presented herein can be used by other researchers to improve their robots.

Gastric emptying in migraine: a comparison with functional dyspepsia.

BACKGROUND/AIMS: Gastric stasis in migraineurs remains controversial. The aim of this study is to investigate gastric emptying (GE) time, and any associations between GE parameters and dyspeptic symptoms among patients with functional dyspepsia (FD) and migraine without any gastrointestinal symptoms during the interictal period. METHODS: We enrolled 27 migraine patients, 32 FD patients and 12 healthy people as controls, and performed GE scintigraphy as gastric function test. Gastrointestinal symptoms were evaluated in the FD and migraine. RESULTS: The age-adjusted mean gastric half-emptying time in FD (125.51 ± 52.55 minutes) patients was longer than in migraineurs (100.82 ± 23.94 minutes, P = 0.035) and controls (95.25 ± 23.29 minutes, P = 0.021). The percentage of gastric retention was higher in FD than in migraine. However, migraineurs did not show an obvious delayed gastric emptying or an increase of gastric retention when compared to the normal controls. The association between each dyspeptic symptom and GE parameters was not significant, but postprandial fullness and early satiety showed a tendency of delayed GE. In migraineurs, GE time did not show significant association with nausea and vomiting during interictal periods. CONCLUSIONS: Delayed GE does not appear to be a mechanism that patients with FD and migraine have in common. Migraineurs without dyspepsia during interictal period had normal GE, and further study for association with FD should be investigated.

Remifentanil prevents tourniquet-induced arterial pressure increase in elderly orthopedic patients under sevoflurane/N2O general anesthesia.

AIMS: Prolonged tourniquet inflation produces a hyperdynamic cardiovascular response. We investigated the effect of continuous remifentanil infusion on systemic arterial pressure, heart rate, and cardiac output changes during prolonged tourniquet use in elderly patients under sevoflurane/N(2)O general anesthesia. METHODS: Thirty female patients scheduled for knee replacement arthroplasty were infused with either remifentanil at a target organ concentration of 2.0 ng/mL (remifentanil group, n = 15) or saline (control group, n = 15) after induction of anesthesia. Anesthesia was maintained with sevoflurane and N(2)O. Heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), cardiac index (CI), total systemic vascular resistance index (TSVRI), BIS, end-tidal sevoflurane concentration (EtSEVO), and end-tidal carbon dioxide concentration (EtCO(2)) were measured during the study period. RESULTS: There were significant differences in mean HR, SAP, DAP, and EtSEVO over time between the groups (P = 0.047, P < 0.001, P = 0.017, and P < 0.001, respectively). There was a statistically significant time trend effect (P < 0.001) in HR, SAP, DAP, and CI between the groups, with a statistically significant time-group interaction between the two groups (P = 0.02, 0.007, 0.001, 0.01, respectively). CONCLUSION: The present study demonstrated that infusion with remifentanil prevented an increase in hemodynamic pressure during tourniquet inflation in elderly patients under sevoflurane/N(2)O general anesthesia.

[The prevalence of Yersinia infection in adult patients with acute right lower quadrant pain].

BACKGROUND/AIMS: Clinical manifestations of intestinal yersiniosis include enterocolitis, mesenteric adenitis, and terminal ileitis presenting with fever, right lower quadrant pain, and leukocytosis. According to a previous Korean study in 1997, Yersinia was revealed in two among 15 adult patients with mesenteric adenitis (13%). However, recent reports on the prevalence of Yersinia infection in adult patients are few. The aim of this study was to investigate the prevalence of Yersinia infection in adult patients with acute right lower quadrant pain. METHODS: Adult patients (>18 years) who visited Eulji medical center, due to acute right lower quadrant pain were enrolled prospectively from December 2007 to July 2009. Abdominal CT, stool culture, serologic test for Yersinia, and Widal test were performed. RESULTS: Among 115 patients, 5 patients were excluded due to positive Widal test or salmonella culture. In 110 patients, abdominal CT showed right colitis in 20 (18.2%), terminal ileitis in 16 (14.5%), mesenteric adenitis in 13 (11.8%), acute appendicitis in 10 (9.1%), acute diverticulitis in 7 (6.4%), non specific mucosal edema in 36 (32.7%) and no specific lesion in 8 (7.3%). Two (1.8%) of the 110 patients had antibodies to Yersinia. One patient showed acute enteritis and the other patient was diagnosed with acute appendicitis and underwent appendectomy. No Yersinia species were grown on stool or tissue culture. CONCLUSIONS: Nowadays, among adult Korean patients presenting with acute right lower quadrant pain, there have been few incidences of Yersinia infection.

Lung diffusion capacity in early cirrhosis: is lung diffusion capacity a predictor of esophageal varices and ascites?

BACKGROUND: Varices and ascites are clinical manifestations of hyperdynamic circulation syndrome originating from increased nitric oxide in cirrhosis. Research was conducted in order to find any correlation between lung diffusion capacity and the presence of varices and ascites in cirrhosis. METHODS: The study was conducted on a total of 120 subjects. Tests for pulmonary function, including carbon monoxide diffusing capacity (DLCO) and fractional exhaled nitric oxide (FENO), were performed. RESULTS: DLCO/alveolar ventilation (VA) values were lower in cirrhosis and chronic liver disease groups than in the control group (3.79 vs. 4.5 vs. 5.1 ml/mmHg/min, p<0.001). DLCO/VA showed a negative correlation with the Child score and the MELD score (r=-0.3 vs. r=-0.41). In patients with varices, the DLCO/VA value was 3.75 ml/mmHg/min, which was lower than the 4.12 ml/mmHg/min observed in patients without varices (p=0.029). FENO levels were higher in the chronic liver disease and liver cirrhosis groups than in the control group. FENO and DLCO showed a negative correlation (r=-0.25, p=0.006). The frequency of significant varix and decompensation were higher in the high FeNO group. CONCLUSIONS: Lung diffusion capacity decreased according to the disease's severity in early cirrhosis, and showed a good correlation with esophageal varices and ascites.

INS/EKF-based stride length, height and direction intent detection for walking assistance robots.

We propose an algorithm used to obtain the information on stride length, height difference, and direction based on user's intent during walking. For exoskeleton robots used to assist paraplegic patients' walking, this information is used to generate gait patterns by themselves in on-line. To obtain this information, we attach an inertial measurement unit(IMU) on crutches and apply an extended kalman filter-based error correction method to reduce the phenomena of drift due to bias of the IMU. The proposed method is verifed in real walking scenarios including walking, climbing up-stairs, and changing direction of walking with normal.

Asymptomatic lymphangioma involving the spleen and retroperitoneum in adults.

Lymphangioma, a benign neoplasm of the lymphatic system, is common in children but rare in adults. Its clinical manifestations include abdominal pain, nausea, vomiting and a palpable mass. However, abdominal sonography or abdominal computed tomography (CT) scan can also incidentally reveal lymphangioma. A larger or symptomatic lymphangioma is treated with total resection to prevent recurrence, infection, torsion and enlargement. Although lymphangioma rarely becomes malignant, its prognosis is generally good. We report a cystic lymphangioma of the spleen and retroperitoneum, which was incidentally found in a 56-year-old man who was hospitalized due to a colon mass. Physical examination showed no specific findings. Abdominal CT revealed a 5.7 cm, non-enhanced multilobulated cystic mass with multiple septa in the spleen and a 10 cm lobulated cystic mass in the paraaortic area. Splenectomy and retroperitoneal resection of the cystic mass were conducted. The endothelium of splenic and retroperitoneal cyst was immunohistochemically stained with D2-40 antibody. The patient was finally diagnosed with splenic cystic and retroperitoneal cavernous lymphangioma.

[Sigmoid colon diverticular bleeding in a 75-year-old woman].

Most common cause of brisk hematochezia is diverticular bleeding in Western countries. It occurs in 15% of patients with diverticulosis and one-third of them appear to be massive. Most of diverticulosis in Western countries occur in the left colon but the right colon is more common in Korea. Especially, the reports of diverticular bleeding on left colon are rare in Korea. We report a case presenting with multiple diverticuli complicated by recurrent massive bleeding restricted to the left colon. 75-year-old female was admitted due to hematochezia and dizziness. On past history, two years and two weeks ago respectively, she was treated of diverticular bleeding with and without diverticulitis. Hemoglobin level was 9.8 g/dL. On Colonoscopy, numerous diverticuli were seen at sigmoid colon upto splenic flexure which showed fresh blood clots in the lumen. We diagnosed her as recurrent massive diverticular bleeding on the sigmoid colon. She received elective laparoscopic left hemicolectomy.

[A case of mucinous noncystic carcinoma of the pancreas].

Mucinous (colloid) carcinoma is defined as pools of stromal extracellular mucin containing scanty, floating carcinoma cells. It is a well-defined entity in breast or large bowel. However, mucinous noncystic carcinoma of the pancreas (MNCC) is uncommon, comprising between 1% and 3% of all carcinomas of the pancreas. In the past, MNCC generally had been categorized together with ordinary ductal adenocarcinoma or misdiagnosed as mucinous cystadenocarcinoma or signet-ring cell carcinoma. The new WHO classification lists MNCC as a variant of ductal adenocarcinoma. Herein, we report a 32-year-old woman with incidentally found pancreatic body mass who underwent subtotal pancreatectomy. She was diagnosed as MNCC histologically.

Giant hyperplasia of the caudate lobe in a patient with liver cirrhosis: case report and literature review.

The caudate lobe often exhibits enlargement and nodularity in cases of cirrhosis, which makes differentiation of hepatocellular carcinoma from other mass-like lesions of the caudate lobe difficult in cirrhotic patients. A 12x6 cm mass-like enlargement of the caudate lobe was incidentally found by computed tomography in a 38-year-old man suffering from alcoholic liver cirrhosis. Magnetic resonance imaging, liver colloidal scan, and sonoguided liver biopsy were used for the differential diagnosis. A literature review revealed two case reports, all of which (like ours) presented with an enlarged caudate lobe supplied with blood via a branch of the portal vein. Therefore, in cases of giant hyperplasia of the caudate lobe, confirmation of the caudate lobe blood supply and the enhancement pattern might be important for the differentiation.

Polycyclic aromatic hydrocarbons by ring-closing metathesis.

A strategy for the synthesis of polycyclic aromatic hydrocarbons (PAHs) by the ring-closing olefin metathesis (RCM) of pendant olefins on a phenylene backbone has been developed. RCM of 2,4',6',2' '-tetravinyl-[1,1';3',1' ']terphenyl and 2,2',5',2' '-tetravinyl-[1,1';4',1']terphenyl affords in high yield the isomeric [a,j] and [a,h] dibenzanthracenes, respectively. In contrast with other intramolecular annulation methods, such as Friedel-Crafts acylations, this reaction is completely regioselective. Since RCM is reversible and PAHs are often thermodynamic sinks, this strategy is an effective and general method for the preparation of PAHs. Density functional theory calculations support these results. Carbon disulfide is a suitable solvent for these reactions.